Commit 8461a3de authored Mar 13, 2015 by Josef Bacik Committed by Chris Mason Mar 13, 2015

Btrfs: fix merge delalloc logic

My patch to properly count outstanding extents wrt MAX_EXTENT_SIZE introduced a
regression when re-dirtying already dirty areas. We have logic in split to make
sure we are taking the largest space into account but didn't have it for merge,
so it was sometimes making us think we were turning a tiny extent into a huge
extent, when in reality we already had a huge extent and needed to use the other
side in our logic. This fixes the regression that was reported by a user on
list. Thanks,

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>

parent 48da5f0a

fs/btrfs/inode.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1592,7 +1592,12 @@ static void btrfs_merge_extent_hook(struct inode *inode,
		return;

		old_size = other->end - other->start + 1;
		new_size = old_size + (new->end - new->start + 1);
		if (old_size < (new->end - new->start + 1))
		old_size = (new->end - new->start + 1);
		if (new->start > other->start)
		new_size = new->end - other->start + 1;
		else
		new_size = other->end - new->start + 1;

		/* we're not bigger than the max, unreserve the space and go */
		if (new_size <= BTRFS_MAX_EXTENT_SIZE) {